Atypical manifestations in CAPS sydrome: not so unfrequent?

Results Rash (14/26), arthritis (14/26), and deafness (12/26) were the most common features. Episodic fever accounted in 8/26 patients. 14/26 patients did not present episodic course and disease onset was over 10 years in 17/26 patients. 2/26 patients developed amyloidotic hemorrhagic cystitis and other 2/26 patients explained olfactive disfunction. Amyloidosis was confirmed in 2/26 patients and considered as probable in other 4/26 patients. Acute phase reactants were normal in 7/26 patients. CIAS1 mutations were identified in 23/26 patients (Ala439Thr in 5, Arg488Lys in 6 and Arg260Trp in 12). 5/6 patients carriers of an heterozigous Arg488Lys mutation were asymptomatic while it failed to isolate any CIAS1 germinal, somatic or mosaic mutation in 3 members of the same pedigree although their clinical profiles were consistent with Muckle-Wells syndrome (1 case) and CINCA / NOMID (2 cases). Conclusions Despite the traditional clinical picture of CAPS includes periodic fever, rash, arthritis and deafness with onset usually <1 year, in its absence CAPS cannot be ruled out. The clinical spectre may vary from the chronic afebrile course, to atypical amyloidosis, or olfactive disfunction. The profile of CIAS1 mutations carriers may include asymptomatic individuals or absence of mutations in pedigrees with several members with a highly suggestive clinical profile of severe variants of CAPS syndrome.